Expansion drum



Patented ct. 1931 NUNITEDsm'rlazs PATENT. ortical RALPH R. OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO UNIVERSAL OIL PRODUCTS COMPANY OF CHICAGO, ILLINOIS, A CORPORATION OF SOUTH .DAKOTA EXPANSION DRUM Application led October 29, 1926. Serial No. 144,975.

The present improvements relate more particularly to a reaction drum or expansion chamber forming part of a tube and drum type of apparatus for the cracking of hydrocarbons under heat and superatmospheric pressure.

More specifically, the present invention is directed. to the idea of,l providing an expansion drum having walls of materially greater thickness adjacent one end relative to the thickness of the walls adjacent the other end, for the purpose of balancing to a certain deree the corrosive effect of compounds prouced in the reaction. v

The walls of materially reater thickness wil be provided where t e corrosion is found to be most active, which in one type of tube and drum apparatus com rises the upper part of the reaction cham r. The use of ari expansion vdrum constructed in accordance with the present invention, would obviate the necessity of discarding expansion chambers when corrosion has reduced the thickness ofthe walls, thus materially prolonging the life and time of use of such drums. Furthermore, the present invention enables the operator to ,have a thick wall where it is required from the standpoint of` corrosion, and to reduce this wall thickness at the other end ofthe vessel where corrosion is negligible. In this manner a drum is rovide which is much lighter than it ot ery wise would be if made of the full thiclmess for its entire length.

Various objects and advantages in addition to the above, will be hereinafter more particularly brought out.

In the drawings,-Fig. 1 is a sectional view of an expansion chamber built in accordance with the present invention.

Fig. 2 is an enlarged fragmentary crossl sectional view of one wall,

Referring more in detail to the drawings, 1

, may designate a suitable-sup `ort and 2 may designate angle irons or ot er analogous supporting elements for supporting the reaction drum. or expansion chamber designated as awhole 3. This chamber. 3 may have a diameter of from three taten ,feetmore or less, and mayhave a height from ve chambers adapted to be disposed in horizontal planes.

This chamber may be provided with the cleanout openings L closed by the removable doors 5, and the chamber inA use may be eX- ternally unheated but insulated asshown at.

6,y if desired. Heated hydrocarbons which may have been heated in a tube still, may be introduced through the transfer line 7 controlled by valve 8 discharging into the interior of the chamber 3`where separation of vapors takes place. These vapors maypass out through vapor outlet pipe 9 controlled by the valve 10. Unvaporized residue may be withdrawn through any of the outlets 11, a suitable valve 12 being manipulated for this purpose. Y

In cracking heavy hydrocarbon oils of relatively low gravity containingy sulphur,

conversion conditions of temperature and superatmospheric pressure, it has been'found that compounds are formed as a result of' the i'eaotion which attack the metal walls of the chamber, eating into said wall and. even--A reducing its thickness. to. the point:

tually where it must be replaced.

It has beenfurther found that this cor-l rosive action is more pronounced. in the vapor space of the reaction drum than in lthe nonvapor space. The discarding of drums in which the wall thickness has been reduced and the replacement of such drums, involvesv expense in material and labor.

The present invention purposes to bal.- ance the corrosive effect by varying the' thickness of the walls so that the walls adjacent the upper part of thel chamber 'be such for instance, as a California oil lunder of materially greater thickness than thewalls l adjacent the lower end, it being'understoodf-. that the `vapor space of Asuch "chamber isl adjacent the upper c1181.` Thls isshown grammatically in the drawings, the thickness of the wall at the oint marked A being materially greater an the thickness of the wall at the point marked B.

One method of constructing a drum of this character, 'particularly where it has substantial height, is to first make tubular sections designated (Fig. 2) as 13, 14 and 15, which sections may be connected by means of electric welding, the welding material being illustrated diagrammatically at-16. 'The thickness of the wall in the section 154may be, for instance, two inches. The thickness of the Wall 14 may taper from two inches at its base, to say four inches at its upper end, the thickness of the wall in the section 13 may be say, four inches.

It is to be understood that these fi r'es are merely illustrative, and any relative t icknesses may be used, which are found most suitable.

Although I have described a drum made up of sections connected by electric welding, it is to be understood of course, that the invention embraces drums made up in an manner, particularly including those in which the sections are connected by rivets or the like. Further, the annular ed instead of abutting as shown, may over ap. y

Although I have illustrated the inside wall of the tank as lying in a strai ht line, with the taper on the outside of t e tank, it is to be understood that I do not wish to be limited in this Way, as the taper may be on the inside of the tank, or partlyyin the inside, and partly on the outside, as desired.

I claim as my invention:

1. A chamber for use with apparatus for cracking hydrocarbons, comprising a metal shell made up of connected sections, and having closed end and side Walls, inlets and outlets associated with said walls, the section or sections adjacent one end of said shell havin a materially greater wall thickness than t e section or sections adjacent the opposite end.

2. A chamber for use with apparatus for cracking hydrocarbons, comprising a metal shell having closed end and side walls, inlets and outlets associated' with said walls, the thickness of said walls being materially eater adjacent the upper endo said shell re ative vto the thickness of said walls adjacent the lower end.

3. An ex ansion drum formin part ofi; tube and rum type of oil crac 11g appa.-

ratus adapted to withstand cracking temper-- atures an pressures comprising an integral base member comprising a flanged cleaning manhole with a removable cover, and a residuum draw off outlet, an integral top member of reater thickness than said base member an havin a flanged cleaning manhole 'with a remova le cover, a mixture inlet and a vapor outlet and a plurality ofnaligned crackin cylindrical sections of intermediate thickness interposed between said base member and said top member, and means for securing said members and sections together to form a pressure tight shell.

4. An expansion drum forming part of a tube and drum type of oil cracking apparatus adapted to withstand cracking temperature and pressures comprising an integral base member comprisin a flanged cleaning manhole with a remova le cover, and a residuum draw off outlet,an integral top member of greater thickness than said base meinber, and having a flanged cleaning manhole with a removable cover, a mixture inlet and a vapor outlet and a plurality of aligned cylindrical sections of intermediate thickness i interposed between said base member and said top member, and means for securing said members and sections together to form a pressure tight shelli said securing means comprising seams of e said shell at the joints.

5. A reaction chamber for hydrocarbon oil cracking apparatus, comprising a cap member, substantially four inches in thickness, a base member of materially less thickness than said cap member, sections interposed between said cap member and said base member, and means fo'r/ securing said members ectric welding encircling Dfiy and sections together to form av pressure tight shell, means for admitting cracked liquid oil to said shell, and means for drawing off vapors therefrom.

6. A reaction chamber for hydrocarbon oil cracking apparatus, comprising a cap portion having an integral flanged cleaning manhole with `a pressure tight removable cover a valved cracked mixture inlet and a valve vapor outlet, a base portion having a similar `cleaning manhole, and an integral residuum draw off outlet, said base portion being of materially less thickness than the cap portion, an intermediate cylindrical portion etween said ca and base portions forming a pressure t1 ht shell.

A reaction c amber for hydrocarbon oil crackin apparatus, comprisin a cap ortion, a ase portion of materia y less thickness than said ca portion and an intermediate portion sai sure tight shell.

8. A reaction chamber for hydrocarbon oil apparatus, comprisin a cap ortion, a ase portion of materia y less thickness than said cap diate portion, sai portions forming a pressure tight shell, means for admitting cracked mixture to said shell and means for taking off vapors from sai shell.

9. A reaction chamber for hydrocarbon oil crackin apparatus, comprisin a cap portion, a ase portion of materia y less thickness than said ca portion and an intermediate portion, sai portions ,forming a presportion and an intermef sure tight shell, means for admitting cracked mixture to said shell ineens for R' Y vapors from said shell, and en integral anged cleaning manhole formed in one of said portions and provided with a removable pressure tight cover.

10. An expansion drum foruse in oil crack- A ing systems comprising a pressure-tight shell of greater thickness at its upper portion than at its lower portion. 11. -An expansion drum for use in oil cracking systems comprising a pressure-tight shell of greater thickness at its upper portion than at lts lower portion, and tapering gradually from said upper portion toward said lower portion. l

I RALPH B. HERRICK. 

